Optical Coherence Tomography (OCT) systems can be used in ophthalmology to generate images of tissue layers. These OCT systems often include an OCT probe that is inserted into the eye to visualize an ophthalmic tissue, such as the retina. The OCT probes often include a handle, connected to the rest of the OCT imaging system by an optical cable and a protruding cannula that is inserted into the patient tissue.
In use, a generated light beam is split into an imaging light beam and a reference light beam. The imaging light beam is guided by the imaging probe at the target tissue. A portion of this imaging light is reflected from a range of depths of the target tissue and is collected through the same probe. The reflected and collected imaging light beam is then interfered with the reference beam, and from the interference an OCT image of the target in a range of depths is generated.
Some OCT systems create an in-depth image corresponding to a target spot: such an image is typically called an A-scan. Other OCT systems are built to scan through a set of target spots and create in-depth images corresponding to these scanned spots. These in-depth images can be assembled into a so-called B-scan, in essence, an XZ or YZ cross-sectional image of the target tissue in a lateral (X or Y) and an in-depth (Z) direction.
Some probes can scan the imaging beam by moving an optical fiber back and forth within the distal region of the cannula. However, the small diameter of the cannula makes it difficult to move the fiber back and forth. Further, the small space available within the imaging probe limits the types of actuators that can move the fiber. Finally, since in several types of usage the OCT probes are disposed after the procedure, their manufacture must be inexpensive.
Accordingly, there is a need for improved devices, systems, and methods that utilize an OCT probe for scanning an imaging beam over a target tissue, including ophthalmic OCT probes that address one or more of the needs discussed above.